1. Field
The present invention relates to a method of forming a friction disc member, such friction members being useful as a component of a clutch or brake assembly. For example, such a clutch or brake assembly may include coaxial input and output members having a pack of annular friction discs arranged therebetween. Certain of the disc members normally have outwardly projecting teeth while others have inwardly projecting teeth for engaging splined surfaces in the input and output members. Alternate discs may have a friction material secured thereto.
2. Prior Art
It is known to form friction discs by a stamping operation in which an annular disc with projecting teeth is punched from sheet metal stock by means of a die set. In such a case, a portion of the edges of the teeth usually remain roughened and beveled with respect to a surface of the blank, whereas it is desirable to provide a smooth edge perpendicular to the surface of the disc for load bearing engagement with mating spline teeth. In order to provide smooth perpendicular edges on the teeth of a disc, the disc may be subjected to an additional finishing operation in which the edges of the teeth are subjected to shaving or upsetting to provide load bearing face for engagement with a spline. The additional operation of shaving or upsetting the faces of the teeth results in additional expense in manufacturing the disc.